The invention relates to a valve according to the preamble to claim 1 for regulating flows of gas and liquid. The valve has a movable means comprising a valve member and a valve stem, at the end of which the member is arranged, for instance, with the aid of a fixed attachment. For the regulating operation, the means provides, together with the body of the valve, the valve housing, an opening area, which can be varied by moving the means in the valve housing linearly in the longitudinal direction of the stem. This movement is controlled by a bearing arrangement contained in the valve housing and intended for the valve stem, which preferably extends through the wall of the valve housing. As a rule, the bearing arrangement consists of a cylindrical portion of the valve means and a number of bearing sleeves attached to the valve housing. The movement is effected by a positioning device, which can be a hydraulic cylinder adapted to act on the valve means. The device is preferably fixed to the other end of the stem. The valve is used, for example, in power plants and the like regulating flows of water vapour and flows of hot water with high pressures and high temperatures and is installed with its valve stem in an essentially horizontal position. The invention also relates to a process for manufacturing a bearing sleeve for the regulating valve.